Recently, various techniques of realizing a high-capacity magnetic recording device (such as an HOD) have been developed. One of the techniques is a recording technique called shingled magnetic recording (SNR) or shingled write recording (SWR). A magnetic recording device adopting the shingled magnetic recording technique is configured, when writing data to a magnetic disk, to write a recording track in such a manner as to partially overlap with the adjacent track. The shingled magnetic recording technique allows an HDD to achieve a higher track density (tracks per inch [TPI]).
Further, there is a recording technique called thermally assisted magnetic recording (TAMR). A magnetic recording device adopting the thermally assisted magnetic recording technique (hereinafter referred to as a thermally assisted magnetic recording device) comprises a light irradiator configured to irradiate a recording layer of a magnetic disk with light (such as near-field light) and a waveguide which transmits light (such as a laser beam) to the light irradiator. According to this magnetic recording device, it is possible to achieve high density recording by irradiating, when writing data, the recording layer of the recording medium with light from the tip of the light irradiator, locally heating the recording layer, and sufficiently lowering the coercivity of the heated portion of the recording layer.
In the thermally assisted magnetic recording device, when the irradiation range of irradiation light changes, the recording width of the write head changes, accordingly.